Rob,

Any chance you could post samples of similar images recorded initially as JPG and RAW? Or at least point to a URL?
I have resisted buying PS CS (have Elements) so far, and want to try and evaluate how big the difference is, and whether, for my less critical eye, it is worth paying for CS.


Thanks

John

On Sat, 25 Sep 2004 10:23:14 +1000, Rob Studdert <[EMAIL PROTECTED]> wrote:

On 24 Sep 2004 at 14:33, Jack Davis wrote:

I'm curious about all things photographic including
digital. Since I own nine 35mm Pentax lenses, seems
logical to check out the *ist D. While several have
been playing with the phrase; "*ist D..what a
wonderful camera", I've also noted the many serious
praises.
Please help me understand what I read under the (more
info) Specification tab on the B&H site:
10D: Raw+Large=8.0MB Fine.
20D: Raw+jpeg(Large)=12.3MB.
*ist D: Large(Raw)=10.5MB (Tiff)=18.1MB
All note as "excluding memory".
The only one which seems to track with its sensor is
the 10D.
Trick wording? Meaningful? ...anyone?

Hi Jack,

These file sizes are not really meaningful, beyond an indication of how many
shots you can expect to cram onto your chosen storage media.


RAW files in their most basic form consist of a transcription of the RAW values
corresponding to each pixel in the array, some of these are image forming and
some are not. Secondly the bit depth of the ADC may be 12 bits but the RAW data
may be padded (with zeros) to provide a 2 byte word or 16 bits per pixel,
obviously these extra 4 bits per pixel are redundant but it still increases the
RAW file size.


On top of this some RAW file formats are stored uncompressed, some are
compressed, most also contain EXIF information which can vary between camera
models and also some (like the *ist D RAW files) can include an embedded JPG
file.


Most cameras offer similar capabilities WRT noise and exposure latitude and
from my experience far more differences will be seen between the various post
processing methods. Generally the in camera processing (TIFF & JPEG) output
really is little indication of the information that can be extracted from most
camera RAW files in post processing.


How does the *ist D's Dynamic Range compare?

The capture latitude of the *ist D is very similar to most other cameras of the
same age (better than most slide film but poorer than the most forgiving colour
neg film) but you won't really get to see what it can do if you don't shoot RAW
and use a good post processing tool like PS CS. The output differences between
the Pentax Photolab program and PC CS RAW is startling, I didn't realize how
bad the Pentax program was (and it was much better than the in camera generated
files).


Cheers,


Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998





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